Dobby for weaving looms with positive movement with one or two cylinders for cards



p 15, 1959 G. PELLIS 2,904,078

DOBBY FOR WEA G LOOMS WITH POSITIVE MOVEMENT WITH ONE TWO CYLINDERS FORCARDS Filed May 28, 1954 3 Sheets-Sheet 1 l I I f/oVAnm PELLIS Sept. 15,1959 G. PELLIS 2,904,073

' DOBBY FOR WEAVING LOOMS WITH POSITIVE MOVEMENT WITH ONE OR TWOCYLINDERS FOR ems Filed Kay 28, 1954 3 Sheets-Sheet 2 nm'mu a L\ .l]

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INVENTOflz- Q flow/mm Pit-L13 Sept. 15, 1959 G. PELLIS 2,904,

DOBBY FOR WEAVING LOOMS WITH POSITIVE MOVEMENT WITH ONE OR TWO CYLINDERSFOR CARDS Filed May 28, 1954 3 Sheets-Sheet 3 I/VVENTOR? QOl/HNN) FELL/3United States Patent DOBBY' FOR WEAVING LOOMS WITH POSITIVE MOVEMENTWITH ONE OR TWO YLINDERS FOR CARDS Giovanni Pellis, Gorizia, ItalyApplication May 28, 1954, Serial No. 432,989" Claims priority,application Italy June. 1, 1953* i 3 Claims; (Cl. 139-77) The dobbydescribed briefly here departs in its new conception from theaforementioned characteristics, and eliminates all the disadvantagescomplained of.

Its characteristics are as follows:

(a) All the controls of the drive mechanism are positive;

(b) Minimum encumbrance and convenient supervision and application ofthe cards;

(.c) Absence of return springs. and thus reliability of operation;

(d) Control by means of chain transmission directly from a shaft of theloom;

(e) Location of the dobby on a supporting bracket at floor levelconnected with the shoulder of the loom, and thus elimination ofvibrations;

(1) All the contrivances are hermetically enclosed in a casing andoperate in an oil bath.

In the attached sheet of drawings, Figure 1 represents part of a dobby,drawn partly in elevation and with some members in section; Figure 2shows in section a modification of a detail; Figure 3 is a generalelevational view of a representative loom on which the dobby is mounted;Figure 4 is a sectional view taken along a line transverse to thelongitudinal axis of the cylinder 1 in Figure 1.

Referring to Figure 3, the loom illustrated includes the usual healdswhich are movable up and down, with respect to a general frame structure31 of the loom, by conventional cranked levers 32 coupled by thrust rods33 to the arm 20 of a treadle of the dobby. The dobby as a whole issituated at the left-hand side of Figure 3, and is illustrated in anddescribed in detail with respect to Figures 1 and 2. A drive for thesprocket 24 in Figure 1 is obtained in the usual way by a chain 34coupling it to a sprocket 35 on the usual main shaft 36 of the loom.

Referring now to Figures 1 and 2, the dobby includes a shaft 2, on whichthe sprocket 24 is keyed, and which carries keyed thereon a scrollcylinder 1 having in its cylindrical surface a scroll groove 27 in whichis engaged a cam follower consisting of a roller 6 mounted on a segment5 provided with peripheral rack teeth and pivoted on a shaft 4. As thecylinder 1 rotates, the helicoidal scroll groove therein causesoscillation of the segment 5 about its pivot shaft 4. The rack teeth ofthe segment 5 mesh with the teeth of a relatively elongated cylindricaldrum 7 having the teeth arranged along the whole of its length. As thesegment oscillates, the drum revolves alternately in one end the otherdirection. Above the "ice drum. are disposed vertically slidable racks 8which are: guided between guide rollers 12 and a rack pinion. 9 which ispermanently meshed. therewith. Each rack, in its uppermost. restposition (as illustrated) is out, of en. gagement at its lower end withthev drum 1. Each rack. carries at its'lower end a detent 13 pivotedv at281 thereona for movement between a first position inwhich its; toothvwill engage with the teeth of the drum 1, anda second position: wherein.its tooth is clear of and will not be, engaged by the teeth of thedrum- 1. The position of en, gagementv or disengagement of. the detent13 is controlled. as follows. It will be appreciated that an exactlysimilar arrangement is: provided foreach of theracks, 8-, but only theright hand. one is illustrated, for clarity of. the drawing. The endwalls of the: cylinder 1 are each provided with an eccentric camminggroove'3, in. which is engaged a. cam follower consisting of a roller 18onan arm, 19. The arm 19 is one arm of a cranked lever pivoted on themachine frame. As the arm 19 is rocked by cam action, the other arm 19amoves upand down about the pivot. This other arm 19a is coupled at itsfree-end to the bridg member 15 which can slide vertically. During, eachfull rotation of the: cylinder 1, each bridge member 15 is lifted andlowered once, the. two being operated 180? out of phase; On each bridgemember 15 is. mounted pivota-hly a: rocker 16 the lower end of which isengaged into arecess in the top of the detent 13. Thelower face of. thebridge member 15 has a knife edge 14 adapted to seat into, correspondingrecesses provided in the top surface of: the detent, thereby topositively lock. the. latter into whichever position it becomes set. Thebridge. membersare alternately rising and fallingv and as they dosotheycause the rockers 16 to engage atone side or the: other ofapreselector cam 17 rockably mounted toabut against stop block 10-andunder they control. of a rod 22 moved longitudinally intoraised andlowered position by the usual control system for the dobby, eg. apunched-card device: of conventional nature. Thus, according. to theposition, of thepreselector 17 determined bythe: pattern, formation.control device of the dobby,v the. rocker 16", when it is raised, willhave its top end moved to right or left as the case may be, whereby thelower end thereof will drive the detent 13 into or out of engagementwith the teeth of the drum 7. Longitudinal movement of the control rods22 thus determines whether or not the respective rack will be caused toreciprocate by engagement with the drum 7, or not. Between the racks isengaged the pinion 9, which is carried at the end of a link 21 connectedto one arm of a cranked treadle rockably mounted on a pivot 26, theother arm 20 of the treadle being coupled to the heald in the mannerdescribed above.

When the rack 8 has reached the end of its upward travel, the tooth ofthe detent 13 remains in engagement with the drum 7 and the detent caneither remain engaged and cause the subsequent descent of the rack 8, orbe disengaged from the drum 7 by action of the rocker 16. A bar 11 isprovided on the drum 7 and is in fact a tooth thereof but made somewhatlonger than the other teeth, as will be most clear from Figure 4 of thedrawing. At the end point of rotation of the drum 7, as in Figure 2, thebar 11 engages against the underside of the rack 8 and presses the rackas a whole upwardly against the stop rod 25 (see Figure 2). Thismomentarily relieves the detent .13 of any frictional engagement withthe teeth of the drum 7, and the detent can thus be more readilydisengaged if required.

In operation, if the control rods 22 are both kept in raised position,neither of the racks 8 are moved, and the arm 20 of the treadle remainsin the position illustrated in Figure 1, i.e. in which the heald islowered. If-

one control rod 22 is raised, and the other remains lowered, one rackwill be engaged with the drum 7 and the other not engaged therewith, sothat the pinion 9 will perform a rolling movement, between the racks, ofamplitude half that of the length of movement of the moving' rack. Whenboth control rods 22 remain in lowered position, both' racks are engagedand moved byv the drum 7, whereby the pinion 9 assumes an intermediateposition shown in broken line in Figure 1, wherein the ann'zo of thetreadle is' moved into another position indicated in broken line inFigure 1, causing the heald to be held in raised position.

The pinion 9 assumes this intermediate position because, whenthe twodetents 13 are engaged with the racks 8 at opposite sides of the drum 7,the two racks 8 are compelled to make equal and opposite movements. Asthe pinion 9 is meshed with both racks it will assume the intermediateposition. The pinion 9 is only moved upwards or downwards out of thisintermediate position when one of the racks remains stationary whilstthe other. moves by reason of engagement with the drum.

' In the modification shown in Figure 2, the pivoted detent 13 of Figure1 is replaced by a horizontally slidable block 29 provided with a detentfor engagement with the drum 7, and operated by exactly similarmechanism to that described precedingly.

I claim e I 1. In a loom dobby, means for causing lifting and loweringmovement of a heald comprising a frame for the loom,atwo-arm treadlelever pivotably mounted on the frame, means for linking one arm of saidtreadle lever to a heald, a link pivotably connected to the other arm ofthe treadle lever, a toothed roller rotatably mounted on the link, apair of spaced parallel racks permanently meshed with the toothed rollerand longitudinally slidable with respect to the frame, a toothed drivingdrum rotatably mounted in the frame adjacent one end of the two rackswhen said racks are in rest position, means for rotary reciprocation ofsaid driving drum, detent means movably mounted on each rack andarranged to be movableinto an engaged position in which they engage withthe driving drum to mesh the rack with the driving drum and causelongitudinal movement of the respective rack, and a disengaged positionwherein they are disengaged from the driving drum, and means forselectively moving one or the other or both of said detent means intoengaged position.

2. In a loom dobby, means for causing lifting and lowering movement of aheald, as claimed in claim 1, wherein the means for rotary reciprocationof the driving drum comprise a rack-toothed segment pivoted on the frameand-meshed with the driving drum, a driven scrollcylinderrotatablymounted in the frame and having a scroll groove cut therein to serve asan axially-acting cam, and a cam-follower roller rotatably mounted onthe toothed segment and engaged in the scroll groove of the cylinder soas to rock the segment as the scroll cylinder rotates.

3. In a loom dobby, means for causing lifting and lowering movement of aheald, as claimed in claim 2, wherein means for selectively moving oneor the other or both of the detent means into engaged position, comprisea bridge member foreach detent slidably vertically on the frame,

an arm coupled to each bridge member, a cam follower roller on each arm,a cam channel provided in each of the two end faces of the scrollcylinder and having said cam follower rollers engaged therein, the shapeof such channels being arranged such that the bridge members ReferencesCited in the file of this patent UNITED STATES PATENTS 240,009 CromptonApr. 12, 1881 240,304 Crompton Apr. 19, 1881 1,877,759 Atwood et a1.Sept. 20, 1932 FOREIGN PATENTS 967,981 France Apr. 5, 1950

